This invention relates generally to semiconductor technology, semiconductor processing, and the formation of complementary metal oxide semiconductor integrated circuits.
Complementary metal oxide semiconductor integrated circuits include NMOS transistors and PMOS transistors. Generally, these transistors may be made by forming a gate dielectric and then forming NMOS and PMOS gate structures on top of that dielectric. The gate electrode structures may be made of polysilicon, silicide, or metal.
A dummy gate electrode, such as a polysilicon gate electrode, may also be formed over a gate dielectric. Then the dummy gate electrode may be removed and replaced with a metal gate electrode. In such a process, different metal gate electrodes may be utilized for the NMOS and PMOS transistors, but a common dielectric is utilized.
Thus, there is a need for complementary metal oxide semiconductor fabrication techniques.